xref: /openbmc/linux/drivers/iio/light/max44000.c (revision 7cf15f42)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * MAX44000 Ambient and Infrared Proximity Sensor
4  *
5  * Copyright (c) 2016, Intel Corporation.
6  *
7  * Data sheet: https://datasheets.maximintegrated.com/en/ds/MAX44000.pdf
8  *
9  * 7-bit I2C slave address 0x4a
10  */
11 
12 #include <linux/module.h>
13 #include <linux/init.h>
14 #include <linux/i2c.h>
15 #include <linux/regmap.h>
16 #include <linux/util_macros.h>
17 #include <linux/iio/iio.h>
18 #include <linux/iio/sysfs.h>
19 #include <linux/iio/buffer.h>
20 #include <linux/iio/trigger_consumer.h>
21 #include <linux/iio/triggered_buffer.h>
22 #include <linux/acpi.h>
23 
24 #define MAX44000_DRV_NAME		"max44000"
25 
26 /* Registers in datasheet order */
27 #define MAX44000_REG_STATUS		0x00
28 #define MAX44000_REG_CFG_MAIN		0x01
29 #define MAX44000_REG_CFG_RX		0x02
30 #define MAX44000_REG_CFG_TX		0x03
31 #define MAX44000_REG_ALS_DATA_HI	0x04
32 #define MAX44000_REG_ALS_DATA_LO	0x05
33 #define MAX44000_REG_PRX_DATA		0x16
34 #define MAX44000_REG_ALS_UPTHR_HI	0x06
35 #define MAX44000_REG_ALS_UPTHR_LO	0x07
36 #define MAX44000_REG_ALS_LOTHR_HI	0x08
37 #define MAX44000_REG_ALS_LOTHR_LO	0x09
38 #define MAX44000_REG_PST		0x0a
39 #define MAX44000_REG_PRX_IND		0x0b
40 #define MAX44000_REG_PRX_THR		0x0c
41 #define MAX44000_REG_TRIM_GAIN_GREEN	0x0f
42 #define MAX44000_REG_TRIM_GAIN_IR	0x10
43 
44 /* REG_CFG bits */
45 #define MAX44000_CFG_ALSINTE            0x01
46 #define MAX44000_CFG_PRXINTE            0x02
47 #define MAX44000_CFG_MASK               0x1c
48 #define MAX44000_CFG_MODE_SHUTDOWN      0x00
49 #define MAX44000_CFG_MODE_ALS_GIR       0x04
50 #define MAX44000_CFG_MODE_ALS_G         0x08
51 #define MAX44000_CFG_MODE_ALS_IR        0x0c
52 #define MAX44000_CFG_MODE_ALS_PRX       0x10
53 #define MAX44000_CFG_MODE_PRX           0x14
54 #define MAX44000_CFG_TRIM               0x20
55 
56 /*
57  * Upper 4 bits are not documented but start as 1 on powerup
58  * Setting them to 0 causes proximity to misbehave so set them to 1
59  */
60 #define MAX44000_REG_CFG_RX_DEFAULT 0xf0
61 
62 /* REG_RX bits */
63 #define MAX44000_CFG_RX_ALSTIM_MASK	0x0c
64 #define MAX44000_CFG_RX_ALSTIM_SHIFT	2
65 #define MAX44000_CFG_RX_ALSPGA_MASK	0x03
66 #define MAX44000_CFG_RX_ALSPGA_SHIFT	0
67 
68 /* REG_TX bits */
69 #define MAX44000_LED_CURRENT_MASK	0xf
70 #define MAX44000_LED_CURRENT_MAX	11
71 #define MAX44000_LED_CURRENT_DEFAULT	6
72 
73 #define MAX44000_ALSDATA_OVERFLOW	0x4000
74 
75 struct max44000_data {
76 	struct mutex lock;
77 	struct regmap *regmap;
78 	/* Ensure naturally aligned timestamp */
79 	struct {
80 		u16 channels[2];
81 		s64 ts __aligned(8);
82 	} scan;
83 };
84 
85 /* Default scale is set to the minimum of 0.03125 or 1 / (1 << 5) lux */
86 #define MAX44000_ALS_TO_LUX_DEFAULT_FRACTION_LOG2 5
87 
88 /* Scale can be multiplied by up to 128x via ALSPGA for measurement gain */
89 static const int max44000_alspga_shift[] = {0, 2, 4, 7};
90 #define MAX44000_ALSPGA_MAX_SHIFT 7
91 
92 /*
93  * Scale can be multiplied by up to 64x via ALSTIM because of lost resolution
94  *
95  * This scaling factor is hidden from userspace and instead accounted for when
96  * reading raw values from the device.
97  *
98  * This makes it possible to cleanly expose ALSPGA as IIO_CHAN_INFO_SCALE and
99  * ALSTIM as IIO_CHAN_INFO_INT_TIME without the values affecting each other.
100  *
101  * Handling this internally is also required for buffer support because the
102  * channel's scan_type can't be modified dynamically.
103  */
104 #define MAX44000_ALSTIM_SHIFT(alstim) (2 * (alstim))
105 
106 /* Available integration times with pretty manual alignment: */
107 static const int max44000_int_time_avail_ns_array[] = {
108 	   100000000,
109 	    25000000,
110 	     6250000,
111 	     1562500,
112 };
113 static const char max44000_int_time_avail_str[] =
114 	"0.100 "
115 	"0.025 "
116 	"0.00625 "
117 	"0.0015625";
118 
119 /* Available scales (internal to ulux) with pretty manual alignment: */
120 static const int max44000_scale_avail_ulux_array[] = {
121 	    31250,
122 	   125000,
123 	   500000,
124 	  4000000,
125 };
126 static const char max44000_scale_avail_str[] =
127 	"0.03125 "
128 	"0.125 "
129 	"0.5 "
130 	 "4";
131 
132 #define MAX44000_SCAN_INDEX_ALS 0
133 #define MAX44000_SCAN_INDEX_PRX 1
134 
135 static const struct iio_chan_spec max44000_channels[] = {
136 	{
137 		.type = IIO_LIGHT,
138 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
139 		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) |
140 					    BIT(IIO_CHAN_INFO_INT_TIME),
141 		.scan_index = MAX44000_SCAN_INDEX_ALS,
142 		.scan_type = {
143 			.sign		= 'u',
144 			.realbits	= 14,
145 			.storagebits	= 16,
146 		}
147 	},
148 	{
149 		.type = IIO_PROXIMITY,
150 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
151 		.scan_index = MAX44000_SCAN_INDEX_PRX,
152 		.scan_type = {
153 			.sign		= 'u',
154 			.realbits	= 8,
155 			.storagebits	= 16,
156 		}
157 	},
158 	IIO_CHAN_SOFT_TIMESTAMP(2),
159 	{
160 		.type = IIO_CURRENT,
161 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
162 				      BIT(IIO_CHAN_INFO_SCALE),
163 		.extend_name = "led",
164 		.output = 1,
165 		.scan_index = -1,
166 	},
167 };
168 
max44000_read_alstim(struct max44000_data * data)169 static int max44000_read_alstim(struct max44000_data *data)
170 {
171 	unsigned int val;
172 	int ret;
173 
174 	ret = regmap_read(data->regmap, MAX44000_REG_CFG_RX, &val);
175 	if (ret < 0)
176 		return ret;
177 	return (val & MAX44000_CFG_RX_ALSTIM_MASK) >> MAX44000_CFG_RX_ALSTIM_SHIFT;
178 }
179 
max44000_write_alstim(struct max44000_data * data,int val)180 static int max44000_write_alstim(struct max44000_data *data, int val)
181 {
182 	return regmap_write_bits(data->regmap, MAX44000_REG_CFG_RX,
183 				 MAX44000_CFG_RX_ALSTIM_MASK,
184 				 val << MAX44000_CFG_RX_ALSTIM_SHIFT);
185 }
186 
max44000_read_alspga(struct max44000_data * data)187 static int max44000_read_alspga(struct max44000_data *data)
188 {
189 	unsigned int val;
190 	int ret;
191 
192 	ret = regmap_read(data->regmap, MAX44000_REG_CFG_RX, &val);
193 	if (ret < 0)
194 		return ret;
195 	return (val & MAX44000_CFG_RX_ALSPGA_MASK) >> MAX44000_CFG_RX_ALSPGA_SHIFT;
196 }
197 
max44000_write_alspga(struct max44000_data * data,int val)198 static int max44000_write_alspga(struct max44000_data *data, int val)
199 {
200 	return regmap_write_bits(data->regmap, MAX44000_REG_CFG_RX,
201 				 MAX44000_CFG_RX_ALSPGA_MASK,
202 				 val << MAX44000_CFG_RX_ALSPGA_SHIFT);
203 }
204 
max44000_read_alsval(struct max44000_data * data)205 static int max44000_read_alsval(struct max44000_data *data)
206 {
207 	u16 regval;
208 	__be16 val;
209 	int alstim, ret;
210 
211 	ret = regmap_bulk_read(data->regmap, MAX44000_REG_ALS_DATA_HI,
212 			       &val, sizeof(val));
213 	if (ret < 0)
214 		return ret;
215 	alstim = ret = max44000_read_alstim(data);
216 	if (ret < 0)
217 		return ret;
218 
219 	regval = be16_to_cpu(val);
220 
221 	/*
222 	 * Overflow is explained on datasheet page 17.
223 	 *
224 	 * It's a warning that either the G or IR channel has become saturated
225 	 * and that the value in the register is likely incorrect.
226 	 *
227 	 * The recommendation is to change the scale (ALSPGA).
228 	 * The driver just returns the max representable value.
229 	 */
230 	if (regval & MAX44000_ALSDATA_OVERFLOW)
231 		return 0x3FFF;
232 
233 	return regval << MAX44000_ALSTIM_SHIFT(alstim);
234 }
235 
max44000_write_led_current_raw(struct max44000_data * data,int val)236 static int max44000_write_led_current_raw(struct max44000_data *data, int val)
237 {
238 	/* Maybe we should clamp the value instead? */
239 	if (val < 0 || val > MAX44000_LED_CURRENT_MAX)
240 		return -ERANGE;
241 	if (val >= 8)
242 		val += 4;
243 	return regmap_write_bits(data->regmap, MAX44000_REG_CFG_TX,
244 				 MAX44000_LED_CURRENT_MASK, val);
245 }
246 
max44000_read_led_current_raw(struct max44000_data * data)247 static int max44000_read_led_current_raw(struct max44000_data *data)
248 {
249 	unsigned int regval;
250 	int ret;
251 
252 	ret = regmap_read(data->regmap, MAX44000_REG_CFG_TX, &regval);
253 	if (ret < 0)
254 		return ret;
255 	regval &= MAX44000_LED_CURRENT_MASK;
256 	if (regval >= 8)
257 		regval -= 4;
258 	return regval;
259 }
260 
max44000_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2,long mask)261 static int max44000_read_raw(struct iio_dev *indio_dev,
262 			     struct iio_chan_spec const *chan,
263 			     int *val, int *val2, long mask)
264 {
265 	struct max44000_data *data = iio_priv(indio_dev);
266 	int alstim, alspga;
267 	unsigned int regval;
268 	int ret;
269 
270 	switch (mask) {
271 	case IIO_CHAN_INFO_RAW:
272 		switch (chan->type) {
273 		case IIO_LIGHT:
274 			mutex_lock(&data->lock);
275 			ret = max44000_read_alsval(data);
276 			mutex_unlock(&data->lock);
277 			if (ret < 0)
278 				return ret;
279 			*val = ret;
280 			return IIO_VAL_INT;
281 
282 		case IIO_PROXIMITY:
283 			mutex_lock(&data->lock);
284 			ret = regmap_read(data->regmap, MAX44000_REG_PRX_DATA, &regval);
285 			mutex_unlock(&data->lock);
286 			if (ret < 0)
287 				return ret;
288 			*val = regval;
289 			return IIO_VAL_INT;
290 
291 		case IIO_CURRENT:
292 			mutex_lock(&data->lock);
293 			ret = max44000_read_led_current_raw(data);
294 			mutex_unlock(&data->lock);
295 			if (ret < 0)
296 				return ret;
297 			*val = ret;
298 			return IIO_VAL_INT;
299 
300 		default:
301 			return -EINVAL;
302 		}
303 
304 	case IIO_CHAN_INFO_SCALE:
305 		switch (chan->type) {
306 		case IIO_CURRENT:
307 			/* Output register is in 10s of miliamps */
308 			*val = 10;
309 			return IIO_VAL_INT;
310 
311 		case IIO_LIGHT:
312 			mutex_lock(&data->lock);
313 			alspga = ret = max44000_read_alspga(data);
314 			mutex_unlock(&data->lock);
315 			if (ret < 0)
316 				return ret;
317 
318 			/* Avoid negative shifts */
319 			*val = (1 << MAX44000_ALSPGA_MAX_SHIFT);
320 			*val2 = MAX44000_ALS_TO_LUX_DEFAULT_FRACTION_LOG2
321 					+ MAX44000_ALSPGA_MAX_SHIFT
322 					- max44000_alspga_shift[alspga];
323 			return IIO_VAL_FRACTIONAL_LOG2;
324 
325 		default:
326 			return -EINVAL;
327 		}
328 
329 	case IIO_CHAN_INFO_INT_TIME:
330 		mutex_lock(&data->lock);
331 		alstim = ret = max44000_read_alstim(data);
332 		mutex_unlock(&data->lock);
333 
334 		if (ret < 0)
335 			return ret;
336 		*val = 0;
337 		*val2 = max44000_int_time_avail_ns_array[alstim];
338 		return IIO_VAL_INT_PLUS_NANO;
339 
340 	default:
341 		return -EINVAL;
342 	}
343 }
344 
max44000_write_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int val,int val2,long mask)345 static int max44000_write_raw(struct iio_dev *indio_dev,
346 			      struct iio_chan_spec const *chan,
347 			      int val, int val2, long mask)
348 {
349 	struct max44000_data *data = iio_priv(indio_dev);
350 	int ret;
351 
352 	if (mask == IIO_CHAN_INFO_RAW && chan->type == IIO_CURRENT) {
353 		mutex_lock(&data->lock);
354 		ret = max44000_write_led_current_raw(data, val);
355 		mutex_unlock(&data->lock);
356 		return ret;
357 	} else if (mask == IIO_CHAN_INFO_INT_TIME && chan->type == IIO_LIGHT) {
358 		s64 valns = val * NSEC_PER_SEC + val2;
359 		int alstim = find_closest_descending(valns,
360 				max44000_int_time_avail_ns_array,
361 				ARRAY_SIZE(max44000_int_time_avail_ns_array));
362 		mutex_lock(&data->lock);
363 		ret = max44000_write_alstim(data, alstim);
364 		mutex_unlock(&data->lock);
365 		return ret;
366 	} else if (mask == IIO_CHAN_INFO_SCALE && chan->type == IIO_LIGHT) {
367 		s64 valus = val * USEC_PER_SEC + val2;
368 		int alspga = find_closest(valus,
369 				max44000_scale_avail_ulux_array,
370 				ARRAY_SIZE(max44000_scale_avail_ulux_array));
371 		mutex_lock(&data->lock);
372 		ret = max44000_write_alspga(data, alspga);
373 		mutex_unlock(&data->lock);
374 		return ret;
375 	}
376 
377 	return -EINVAL;
378 }
379 
max44000_write_raw_get_fmt(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,long mask)380 static int max44000_write_raw_get_fmt(struct iio_dev *indio_dev,
381 				      struct iio_chan_spec const *chan,
382 				      long mask)
383 {
384 	if (mask == IIO_CHAN_INFO_INT_TIME && chan->type == IIO_LIGHT)
385 		return IIO_VAL_INT_PLUS_NANO;
386 	else if (mask == IIO_CHAN_INFO_SCALE && chan->type == IIO_LIGHT)
387 		return IIO_VAL_INT_PLUS_MICRO;
388 	else
389 		return IIO_VAL_INT;
390 }
391 
392 static IIO_CONST_ATTR(illuminance_integration_time_available, max44000_int_time_avail_str);
393 static IIO_CONST_ATTR(illuminance_scale_available, max44000_scale_avail_str);
394 
395 static struct attribute *max44000_attributes[] = {
396 	&iio_const_attr_illuminance_integration_time_available.dev_attr.attr,
397 	&iio_const_attr_illuminance_scale_available.dev_attr.attr,
398 	NULL
399 };
400 
401 static const struct attribute_group max44000_attribute_group = {
402 	.attrs = max44000_attributes,
403 };
404 
405 static const struct iio_info max44000_info = {
406 	.read_raw		= max44000_read_raw,
407 	.write_raw		= max44000_write_raw,
408 	.write_raw_get_fmt	= max44000_write_raw_get_fmt,
409 	.attrs			= &max44000_attribute_group,
410 };
411 
max44000_readable_reg(struct device * dev,unsigned int reg)412 static bool max44000_readable_reg(struct device *dev, unsigned int reg)
413 {
414 	switch (reg) {
415 	case MAX44000_REG_STATUS:
416 	case MAX44000_REG_CFG_MAIN:
417 	case MAX44000_REG_CFG_RX:
418 	case MAX44000_REG_CFG_TX:
419 	case MAX44000_REG_ALS_DATA_HI:
420 	case MAX44000_REG_ALS_DATA_LO:
421 	case MAX44000_REG_PRX_DATA:
422 	case MAX44000_REG_ALS_UPTHR_HI:
423 	case MAX44000_REG_ALS_UPTHR_LO:
424 	case MAX44000_REG_ALS_LOTHR_HI:
425 	case MAX44000_REG_ALS_LOTHR_LO:
426 	case MAX44000_REG_PST:
427 	case MAX44000_REG_PRX_IND:
428 	case MAX44000_REG_PRX_THR:
429 	case MAX44000_REG_TRIM_GAIN_GREEN:
430 	case MAX44000_REG_TRIM_GAIN_IR:
431 		return true;
432 	default:
433 		return false;
434 	}
435 }
436 
max44000_writeable_reg(struct device * dev,unsigned int reg)437 static bool max44000_writeable_reg(struct device *dev, unsigned int reg)
438 {
439 	switch (reg) {
440 	case MAX44000_REG_CFG_MAIN:
441 	case MAX44000_REG_CFG_RX:
442 	case MAX44000_REG_CFG_TX:
443 	case MAX44000_REG_ALS_UPTHR_HI:
444 	case MAX44000_REG_ALS_UPTHR_LO:
445 	case MAX44000_REG_ALS_LOTHR_HI:
446 	case MAX44000_REG_ALS_LOTHR_LO:
447 	case MAX44000_REG_PST:
448 	case MAX44000_REG_PRX_IND:
449 	case MAX44000_REG_PRX_THR:
450 	case MAX44000_REG_TRIM_GAIN_GREEN:
451 	case MAX44000_REG_TRIM_GAIN_IR:
452 		return true;
453 	default:
454 		return false;
455 	}
456 }
457 
max44000_volatile_reg(struct device * dev,unsigned int reg)458 static bool max44000_volatile_reg(struct device *dev, unsigned int reg)
459 {
460 	switch (reg) {
461 	case MAX44000_REG_STATUS:
462 	case MAX44000_REG_ALS_DATA_HI:
463 	case MAX44000_REG_ALS_DATA_LO:
464 	case MAX44000_REG_PRX_DATA:
465 		return true;
466 	default:
467 		return false;
468 	}
469 }
470 
max44000_precious_reg(struct device * dev,unsigned int reg)471 static bool max44000_precious_reg(struct device *dev, unsigned int reg)
472 {
473 	return reg == MAX44000_REG_STATUS;
474 }
475 
476 static const struct regmap_config max44000_regmap_config = {
477 	.reg_bits		= 8,
478 	.val_bits		= 8,
479 
480 	.max_register		= MAX44000_REG_PRX_DATA,
481 	.readable_reg		= max44000_readable_reg,
482 	.writeable_reg		= max44000_writeable_reg,
483 	.volatile_reg		= max44000_volatile_reg,
484 	.precious_reg		= max44000_precious_reg,
485 
486 	.use_single_read	= true,
487 	.use_single_write	= true,
488 	.cache_type		= REGCACHE_RBTREE,
489 };
490 
max44000_trigger_handler(int irq,void * p)491 static irqreturn_t max44000_trigger_handler(int irq, void *p)
492 {
493 	struct iio_poll_func *pf = p;
494 	struct iio_dev *indio_dev = pf->indio_dev;
495 	struct max44000_data *data = iio_priv(indio_dev);
496 	int index = 0;
497 	unsigned int regval;
498 	int ret;
499 
500 	mutex_lock(&data->lock);
501 	if (test_bit(MAX44000_SCAN_INDEX_ALS, indio_dev->active_scan_mask)) {
502 		ret = max44000_read_alsval(data);
503 		if (ret < 0)
504 			goto out_unlock;
505 		data->scan.channels[index++] = ret;
506 	}
507 	if (test_bit(MAX44000_SCAN_INDEX_PRX, indio_dev->active_scan_mask)) {
508 		ret = regmap_read(data->regmap, MAX44000_REG_PRX_DATA, &regval);
509 		if (ret < 0)
510 			goto out_unlock;
511 		data->scan.channels[index] = regval;
512 	}
513 	mutex_unlock(&data->lock);
514 
515 	iio_push_to_buffers_with_timestamp(indio_dev, &data->scan,
516 					   iio_get_time_ns(indio_dev));
517 	iio_trigger_notify_done(indio_dev->trig);
518 	return IRQ_HANDLED;
519 
520 out_unlock:
521 	mutex_unlock(&data->lock);
522 	iio_trigger_notify_done(indio_dev->trig);
523 	return IRQ_HANDLED;
524 }
525 
max44000_probe(struct i2c_client * client)526 static int max44000_probe(struct i2c_client *client)
527 {
528 	struct max44000_data *data;
529 	struct iio_dev *indio_dev;
530 	int ret, reg;
531 
532 	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
533 	if (!indio_dev)
534 		return -ENOMEM;
535 	data = iio_priv(indio_dev);
536 	data->regmap = devm_regmap_init_i2c(client, &max44000_regmap_config);
537 	if (IS_ERR(data->regmap)) {
538 		dev_err(&client->dev, "regmap_init failed!\n");
539 		return PTR_ERR(data->regmap);
540 	}
541 
542 	mutex_init(&data->lock);
543 	indio_dev->info = &max44000_info;
544 	indio_dev->name = MAX44000_DRV_NAME;
545 	indio_dev->channels = max44000_channels;
546 	indio_dev->num_channels = ARRAY_SIZE(max44000_channels);
547 
548 	/*
549 	 * The device doesn't have a reset function so we just clear some
550 	 * important bits at probe time to ensure sane operation.
551 	 *
552 	 * Since we don't support interrupts/events the threshold values are
553 	 * not important. We also don't touch trim values.
554 	 */
555 
556 	/* Reset ALS scaling bits */
557 	ret = regmap_write(data->regmap, MAX44000_REG_CFG_RX,
558 			   MAX44000_REG_CFG_RX_DEFAULT);
559 	if (ret < 0) {
560 		dev_err(&client->dev, "failed to write default CFG_RX: %d\n",
561 			ret);
562 		return ret;
563 	}
564 
565 	/*
566 	 * By default the LED pulse used for the proximity sensor is disabled.
567 	 * Set a middle value so that we get some sort of valid data by default.
568 	 */
569 	ret = max44000_write_led_current_raw(data, MAX44000_LED_CURRENT_DEFAULT);
570 	if (ret < 0) {
571 		dev_err(&client->dev, "failed to write init config: %d\n", ret);
572 		return ret;
573 	}
574 
575 	/* Reset CFG bits to ALS_PRX mode which allows easy reading of both values. */
576 	reg = MAX44000_CFG_TRIM | MAX44000_CFG_MODE_ALS_PRX;
577 	ret = regmap_write(data->regmap, MAX44000_REG_CFG_MAIN, reg);
578 	if (ret < 0) {
579 		dev_err(&client->dev, "failed to write init config: %d\n", ret);
580 		return ret;
581 	}
582 
583 	/* Read status at least once to clear any stale interrupt bits. */
584 	ret = regmap_read(data->regmap, MAX44000_REG_STATUS, &reg);
585 	if (ret < 0) {
586 		dev_err(&client->dev, "failed to read init status: %d\n", ret);
587 		return ret;
588 	}
589 
590 	ret = devm_iio_triggered_buffer_setup(&client->dev, indio_dev, NULL,
591 					      max44000_trigger_handler, NULL);
592 	if (ret < 0) {
593 		dev_err(&client->dev, "iio triggered buffer setup failed\n");
594 		return ret;
595 	}
596 
597 	return devm_iio_device_register(&client->dev, indio_dev);
598 }
599 
600 static const struct i2c_device_id max44000_id[] = {
601 	{"max44000", 0},
602 	{ }
603 };
604 MODULE_DEVICE_TABLE(i2c, max44000_id);
605 
606 #ifdef CONFIG_ACPI
607 static const struct acpi_device_id max44000_acpi_match[] = {
608 	{"MAX44000", 0},
609 	{ }
610 };
611 MODULE_DEVICE_TABLE(acpi, max44000_acpi_match);
612 #endif
613 
614 static struct i2c_driver max44000_driver = {
615 	.driver = {
616 		.name	= MAX44000_DRV_NAME,
617 		.acpi_match_table = ACPI_PTR(max44000_acpi_match),
618 	},
619 	.probe		= max44000_probe,
620 	.id_table	= max44000_id,
621 };
622 
623 module_i2c_driver(max44000_driver);
624 
625 MODULE_AUTHOR("Crestez Dan Leonard <leonard.crestez@intel.com>");
626 MODULE_DESCRIPTION("MAX44000 Ambient and Infrared Proximity Sensor");
627 MODULE_LICENSE("GPL v2");
628